NEAR TWO HARBORS — Twelve-year-old Owen Cruikshank strides purposefully along the cobblestone beach of Lake Superior. He checks the GPS unit he holds in one hand.

“Three hundred fifty-one feet,” Owen announces.

Owen is leading his dad, Dan Cruikshank, and two siblings — Rosie, 5, and Reed, 3 — along the beach at Flood Bay, just northeast of Two Harbors. They’re searching for “Wisdom.” That’s the name of a cache that is hidden somewhere nearby. Within 351 feet, to be precise.

Dan Cruikshank of Two Harbors and his children look through the contents of a cache they’ve just found while geocaching in the woods near Flood Bay, just northeast of Two Harbors. From left are Reed, 3; Owen, 12; and Rosie, 5. Owen holds a scroll with bits of wisdom written on it.

Dan Cruikshank of Two Harbors and his children look through the contents of a cache they’ve just found while geocaching in the woods near Flood Bay, just northeast of Two Harbors. From left are Reed, 3; Owen, 12; and Rosie, 5. Owen holds a scroll with bits of wisdom written on it.

The Cruikshanks are among millions of people — and at least 15,000 in Minnesota — who have discovered the hide-and-seek joy of geocaching. Geocachers hide small, weatherproof boxes containing trinkets and log books all over the world, then list their exact coordinates on a Web site so that other geocachers can go find them.

The Cruikshanks, of Two Harbors, are casual geocachers. In a year and a half, they’ve found 11 caches. At the other end of the spectrum is someone like Duluth’s Tom Heikkila, who has nearly 3,100 “finds” since he began geocaching in 2004.

Geocaching enjoys conflicting images. Some find it a fun and harmless way to enjoy the outdoors, a blend of high-tech navigation and boot-leather effort. Others consider it an uncool endeavor, a contrived way to be in the woods. Still others object to the whole business of littering the landscape with trinkets.

Dan Cruikshank admits it attracts a unique kind of person.

“This is kind of a nerd sport,” he says. “A lot of nerds and geeks do it.”

Most people wouldn’t consider the Cruikshanks nerds. They’re just a regular family that enjoys getting out for short hikes in the woods. While Rosie dawdles down the beach looking for agates and Reed shuffles along with a plastic drill, Owen is up ahead, homing in on “Wisdom,” which was placed somewhere here by geocachers called “Team Redbone” in October 2007.

Before leaving on this search, the Cruikshanks had gone online to www.geocaching.com to select a cache and download its coordinates. Once at Flood Bay, they entered those coordinates into the GPS receiver.

“Two hundred feet,” Owen calls.

He keeps walking.

“One hundred feet,” he calls. “Now it says it’s over that way.”

Owen is following the map unfolding on Dan’s GPS unit, which uses satellite triangulation to pinpoint spots on Earth. It’s usually accurate to within 15 to 20 feet of a cache, Dan says. Lots of young people are drawn to geocaching because they like the high-tech aspect of GPS navigation.

The GPS leads Owen and his entourage into the woods and within 12 feet of the cache. The Cruikshanks find themselves in a thick tangle of aspen, spruce and balsam fir just behind the beach. Now the intense searching begins.

“It could be in a tree hole,” Rosie offers. “We found one in a tree hole before.”

Finally, Dan spots an unnatural jumble of logs at the base of an aspen, and Owen uncovers an Army-drab ammunition box. It’s “Wisdom.”

Quickly, Owen opens it up to discover a lengthy scroll upon which previous geocachers have written words of wisdom. But that’s not all. The box also contains a stuffed animal, a toy kaleidoscope, a coin, a button and a medallion.

This process of discovery is at the heart of geocaching, Dan says.

“It appeals to the kid in you,” he says. “It’s like a treasure hunt.”

Rosie knows what she likes about finding a cache.

“You get to take stuff out,” she says.

She likes the kaleidoscope, so she claims it. Dan, knowing the kids like to collect small items from geocaches, always brings something along to replace them. His geocaching user name is “agatedan,” so he always brings along an agate to place in a cache. This time, he also throws in a couple of small carabiners, the spring-loaded clips used by rock climbers.

Geocachers have been discovering caches such as “Wisdom” since 2000. That’s when geocaching began on the West Coast, shortly after the U.S. government had made more satellites accessible to consumer-model GPS receivers. An Oregon man placed a small cache, then gave its coordinates to his friends to see if they could find it. Now, according to geocaching.com, some 619,000 caches have been hidden worldwide.

The Cruikshanks came into geocaching accidentally when they stumbled upon a cache north of Two Harbors. Dan went to the geocaching Web site to learn more about the activity. Not much later, he won a GPS unit at a conference.

For some geocachers, such as Duluth’s Heikkila, the activity becomes a bit of a passion. For the Cruikshanks, it’s a more casual thing, a way for Dan to be out in the woods with his kids.

At the cache, the kids listen as Dan reads from the scroll found in Wisdom.

“When you go sometimes into a situation with nothing planned, wonderful things happen,” credited to Jerry Garcia by “dlhcacher,” who happens to be Heikkila.

The Cruikshanks leave a bit of their own wisdom. On the scroll, Dan writes, “Live, love and hike!” Owen carefully replaces the scroll in the ammo can and stows it at the base of the tree, covering it with the branches for the next finder.